# Ever Wondered Why Your Measuring Tape Has Black Diamonds On It. Mystery Solved

Advertisement

While every person knows how to use a measuring tape, almost none of us have any idea of the small markings and numerals that are subtly placed in between the numbers and dashes. Today, we are going to give a full low down on all the nitty-gritty of a measuring tape so that you work as a professional next time.

We start off with the obvious details: the larger numbers at the top represent inches, while the smaller numbers on the bottom of the tape indicate centimeters.

These circled Roman numerals are sometimes present in between and represent the level of accuracy of the measuring tape. The smaller the numerals, the more accurate your tape is. The tapes that don’t have these marks have no guaranteed level of accuracy.

The circled numbers on the left, shown in the picture below, represent the total length of the tape measure. The manufacturers print the length on the tape as it is required by the law.

Now coming to the mysterious black diamonds, which may look like dark circles.

These diamonds appear at the 19.2-inch mark and allow the construction workers to make five trusses in an eight-foot space. Truss layouts or items are usually eight feet in length, and when you divide 8 feet (96 inches) into five, you get 19.2 inches.

This accuracy would be difficult to achieve without these marks because of the decimal point. Hence, the diamonds are placed to end the hassle altogether. While the presence of these diamonds may seem trivial to the average Joe; it is vital for the construction workers as most of the American construction materials come in lengths of eight feet.

You now are an expert tape measurer!

You’re welcome!

Advertisement

## Comments 19

1. HMS says:

Ignorance is bliss. I once suggested metric to a calm neighbor who was a banker. He went blastic that I would suggest a non patriotic scheme used by all but the USA and a few 3rd countries. A 1x1x1 cm of water weighs a gram. To heat it 1 degree takes a thermal unit. I can make a box that holds a liter of water, know it’s 1000 cubic centimeters, know it weighs 1kg, and how much heat to warm it 10 degrees without a calculator. But no, here I’m on a ladder trying to 2 feet 3-7/64 inched by 4 so my coat pegs will be even…..Also those tapes with inches and mm are useless, I end up with mm aganist the object trying to sight across the tape to read inches. If I have to use inches I want it on both edges of the tape.

2. Trevor Mynhardt says:

I guess most Americans are not clever enough to learn or understand the metric system

3. Marc says:

I would love to have a tape measure which bottom number are twice the top. Any idea where to buy one?

1. Roberto Mola says:

…and I would love a tape with ONLY millimeters units! Still looking for one to buy.

1. Jason says:

I have seen all metric tapes at Home Depot and Lee Valley

4. BSchultz says:

Thanks a lot for the new information. My bet is a lot of us so called backyard carpenters didn’t know about the black diamond’s. I do now and it could come of use in the future. Thanks again

5. Rbormann says:

The Imperial system is used by USA, Myanmar and Liberia. Ita a small world indeed. LOL.

6. Rbormann says:

The Imperial system is used by USA, Myanmar and Liberia. Ita a small world indeed. LOL.

7. Chimezie says:

Engineering makes the world go round

8. Livio says:

8 feet? 96 inch? LOL, when you pass to the decimal system it will always be too late…

1. Tony says:

I still use feet and inches, it is used by millions and is the World standard.

1. Tony Bucca says:

WORLD STANDARD???? ONLY 3 countries use the Imperial system….

2. Anders says:

No, it’s not! The most country uses the metricsystem.

3. Roberto Mola says:

World standard??!! Hahahaha!!!!You probably never left your neighborhood and are discoursing about “the world”. Check your computer on google, wikipedia or ANY other source. Now you can continue transforming inches in decimal to enable arithmetics…

2. LeLoupBlanc says:

Actualy, divide 250 cm by 5 is quite more easy and not necessitate this black diamonds. It is interesting to see how they find a tricky way to ease the work with the old system rather than use a clearly simple system !

1. Trevor Mynhardt says:

I guess most Americans are not clever enough to learn or understand the metric system

1. Sherrie Olson says:

Right or wrong the imperial system was what we were taught. Clever has nothing to do with it! Why would one learn a system that isn’t used in their country? It is as common to us as being rude is for some folks.

2. Roberto Mola says:

Exactly…

1. Roberto Mola says:

When I told “exactly” above I was addressing Mr. LeLoupBlanc. To Ms. Sherrie Olson I need to say that your text is nonsense: Even being wrong you’re using because your teachers told so??!! If imperial was better I would override my school and buy inches and feet tapes…

Back to
log in